The present invention relates to a novel and useful dental impression dam system.
Dental impression trays are employed generally to hold fluid impression material. The tray and material are inserted into a patient's mouth, and pressed onto the teeth of the patient to produce a pattern representing a dental formation. The fluid dental impression material then hardens and is used to produce a crown, bridge, and the like.
In most cases, the dental practitioner must introduce an adequate amount of material to produce a proper dental impression. However, in certain cases, excess material may be employed to insure against a deficiency of dental impression material during this process. However, the use of excess material creates a problem of the dental impression material overflowing the tray and gagging or choking the patient.
This problem has been recognized and various impression trays have been devised to correct the same. For example, U.S. Pat. Nos. 273,833, 4,652,237, and European Patent Application EPO 95038282 describe dental impression trays having dams at the end portions to prevent movement of impression material into the throats of the user.
U.S. Pat. Nos. 210,407 and 538,204 show dental impression trays which employ a soft dam material at the end portions thereof to hold the impression material in the tray and cushion the bite of the user on the impression material.
U.S. Pat. No. 3,534,475 shows an attachment for a dental impression tray in the form of a series of hooks which are meant to imbed excess dental impression tray material and hold the same away from the throat of the user.
A problem still remains in dental impression cup and trays in that the dams do not prevent the formation of a layer of excess dental impression material outside the tray which may separate from the prior art demand the main body of the impression material and cause a choking or gagging problem with the user or patient.
A dental impression dam system which solves the problems noted in the prior art would be a notable advance in the dental field.